Your title depends on what your text and reasons are specifically about and what the information you are given is, however I would choose whichever one fits your information the best. However, they all are talking about bicycles. I would most likely choose the health benefits of bicycling.
Answer:
compound complex sentence
Answer: when a writer points to a problem caused by social customs without explicitly challenging those customs.
A social commentary is the use of rhetorical devices in order to comment on the problems of society. This is usually a critique, and it is intended to promote change or to appeal to people's sense of justice. However, when this commentary is done subconsciously, the writer points towards the problem but does not explicitly challenge the customs.